...snip...
We're talking about 1 year of testing (up to today), 4-5 Months on a special testnet, and 7-8 Months on the Bitcoin testnet. That's as close as it gets to having it live on the main chain.
...snip...
Deploying Segwit on a live altcoin network would be
MUCH closer to having it on the main chain. Testnet coins have 0 value. Until there is value at risk, there is no reason other than ego to search for a flaw. It is utterly irresponsible to put a
18 billion dollar network at risk when the value of the networks it has been tested on stands at
exactly $0.